<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
  <script>
    var str = '';
    for (var i = 0; i <4; i++) {
      for (var j = 0; j < 4; j++) {
        str += '☆'

      }
      str += '\n';
    }
    console.log(str);
  </script>
</body>
</html>